Wrench construction



4Oct. 26, 1943. L. w. JOHNSON WRENCH CONSTRUCTION Filed March 15, 1941 lwlvlm lill Patented Oct. 26, 1943 UNITED STATES PATENT oFFicE v 2,332,972 `WRENCH CONSTRUCTION Leonard W. Johnson, deceased, late of Batavia, Ill., by Helena. E. Johnson, executrix, Batavia, Ill., assignor to Helena E. Johnson Application December 15, 1941, Serial No. 423,076

3 Claims.

'I'his invention relates to tension wrenches, and has particular reference to a, wrench or the slip joint variety having a circular work engaging boss with two oppositely disposed latch members on each side of the boss, and two handles, whereby a balanced thrust is maintained upon the work engaging boss and through the use of the two oppositely disposed handles a balanced torsional movement is imparted to the wrench, obviating the possibility of side strain or friction due to the canting of the parts in the wrench itself, whereby the wrench is rendered more accurate in service than wrenches of this type heretofore employed.

Another object of this invention is the provision of a torsion wrench having a pair of oppositely disposed handles to enable eiclent operation of the wrench to be secured and likewise to render the wrench available for use with either hand in turning down nuts, so that during use of the wrench if the hand of the operator becomes tired he can change to the other hand, a desirable feature because of the speed with which these wrenches are used on assembly lines, reaching as high as twenty pulls per minute in some classes of work.

A further object of the invention is the provision of a wrench of the slip joint variety in which a pair of latch members in frictlonal engagement with a boss is used, the force of the boss which is exerted upon the workpiece being determined by the amount of friction between the latch members, and in which it is desirable to reduce to the lowest possible point the friction of other operating parts of the wrench or at least render the wrench uniform in its operation.

Another and further object of this invention is the provision of a torsion wrench having oppositely disposed balance thrust members so that the boss is held in balanced relation at all times, and to this extent is an improvement upon the wrench described and Aclaimed in the copending application of Leonard W. Johnson, Serial No.`

istry of the slots in the nuts with holes through r the bolts, for insertion of cotter pins. It further provides a wrench by which nuts can be backed oil, if desired, or which when set can be backed up and reset to secure accuracy. This is necessary at certain times due to the inaccuracy of the possible for an operator to properly pull these i tension wrenches and at the same time keep his attention fixed on sight indicating means.

These and other objects of the invention will be more fully and better understood by reference to the accompanying sheet of drawings, and in Which- Figure 1 is an elevational view of my improved wrench;

Figure 2 is a plan sectional view of the operating parts at one end of the wrench; and

Figure 3 is a vertical sectional view taken through the center of Figure 2.

Referring now specifically to the drawing, and in which like reference characters refer to like parts throughout, a circular head II) is provided having oppositely extending hollow arms Il and I2 projecting therefrom, to which hollow extensions i3 and I4 are secured by means of rivets I5, I5 or any other appropriate fastening means. To the outer ends of the hollow extensions I3 and I4, respectively, are mounted hollow handles I8, I6, the extensions I3 and I t extending into sockets formed in thehandles I6, I6 respectively, and being secured in position by means of screws l6a, IIia.

-Mounted within the circular head I0 is a boss I'I having trunnions I8 and I9 axially positioned upon the boss I'I upon each side thereof, the trunnion I9 being extended to form a squared end 20 forming a work-engaging member and adapted to t in the usual cap used for securing a wrench to nuts in the operation of wrenches of this type. The trunnion I8 is tted into an opening formed in the head Ill, while the opposite trunnion I9 is fitted into an opening formed in a cap 2| which is secured to the head-IIl in any approved manner and which serves to hold the boss I'I in operative position in the head I0. The boss II has recesses 22 and 23 formed therein, with walls 24 and 25 at one side of the recesses which are inclined slightly rearwardly from a radial line extending across the face of the boss II and from the center thereof, these recesses being positioned on opposite sides of the outer periphery of the boss I 'I. Another recess 26 is formed in the outer peripheryof the boss I'I, within which a stop 2l is positioned, this stop having a threaded end 28 which is in engagement with the threaded 4opening formed through the wall of the head Il). The stop 21 prevents the head l@ from rotating about the boss l1 except in a limited manner, and enables the wrench to be used for the tightening of nuts slightly beyond the tension for which the wrench isset, if desired, to secure proper registryof the channels in castellated nuts during the operation oi the wrench.

A pair of latch members 23 and 29 is mounted in the arms Il and i2, respectively, these latch members having angularly disposed faces which nt against the boss ll at the bottom of the recesses 22 and 23, respectively, and have slightly rounded nose portions 3o, 3i! so that during lcontinuous operation of the wrench they are not apt to crack the boss adjacent the walls 2li and 25 of the boss il. Springs 3i and 32 are mounted in the extensions i3 and it, respectively, with' followers 35?, 33 being provided which have indicators iid, 3d thereon. These indicators extend through slots 35 in thev extensions and it, and are adapted to indicate pressures by graduations apl pearing upon plates t, 3e secured to the extensions i3 and ifi, respectively. Threaded meinbers 3i are mounted in webs 38 :forming part oi the handle it, and extend rearward with squared recesses 39 therein for the reception of a wrench or other appropriate tool by means of,

which the proper and desired compression may be placed upon the springs Si and 32 to secure the desired friction between the latch members 28 and 2Q and the boss il. Rubber iinger grips dt, il@ are provided on the handles iti, it, respectively, to provide ease and sureness oi grip for the operator in using the wrench. A grease nipple di is mounted in the wall of the head it so that lubricant can be forced through this member into the interior of the head i@ and around the boss il for properly and adequately lubricating the working parts of the Wrench.

In operation of the Wrench it will 'ne understood that the threaded members 3l! are set to the proper location to secure the desired compression on the springs .il and 32, this compression being measured by the graduated markings appearing upon the plates 36, 36, which has been predetermined. If it is desired to turn a nut down to. say, 80 poundsv tension, the figure now commonly accepted to be the proper one in most automobile motors, the members 3l can be turned until each one of them registers 40 pounds, one1 half of the desired tension, and the wrench used to turn the nut down in the usual manner. When the desired resistance of the nut is reached, the latch members will slip in the recesses, not entirely out of them but enough so the operator can feel the slippage as he is pulling on the handles, allowing the head l to rotate a slight distance around the boss ll or until it engages on stop 21. This will be sufficient to indicate to the workman that the desired tension has been reached and the wrench can be removed and applied to another nut. The stop performs the function also of preventing the wrench from spinning around on the boss, which might result in injury to a workman if, in pulling a nut up, his foot lshould slip on a greasy oor when the nut has been turned to the desired tension an the wrench released.

II, because ofA imperfections in the thread, the workman is not satisfied that the nut is tted properly on the bolt at the tension desired, the force on the Wrench is reversed by turning it in a counterclockwise direction, in which position the latch members 28 and 29 engage against the surfaces 24 and 25 so that thenut can be backed up or loosened slightly or removed en' ,tirely if desired, and then pulled down to the set and exert a movement on the wrench in a clockwise direction. Due to the fact that both the springs 3l .and ft2 are placed under the same compression, the boss is, in effect, placed in a floating position inside of the head l@ and there is not the tendency to cant, producing friction on one side of the trunnions it and i9, as would be the case if only one latch member were used or they were placed in any other than oppositely disposed positions to each other. Because of the fact that these latch members 28 and 29 are exerting a pressure upon the boss il in opposite directions, the full force oi the rotative movement oi the handles is applied directly to the boss l? so that friction loss is overcome and the wrench is more accurate than if these opposed members were not used.

It has been found in practice that accuracy in turning down nuts, particularly upon heads of motors, is highly desirable because if they are not turned down uniformly the expansion and contraction of the metal making up the Walls o the cylinder may distort the cylinder until it is out of round, causing loss of power, oil leakage and improper functioning of the motor. Therefore, through the use of the opposed latch members the accuracy of the wrench is materially in-1 creased, thereby adding materially to its eiiectiveness in applying nuts under the proper tension in a variety of operations, particularly with respect to internal combustion engines of all types used in automobiles, airplanes, trucks and the like.

While having described more or less precisely the details of construction, it is not wished to be understood as being limited thereto, as changes in form and the proportion of parts and the substitution of equivalents as circumstances may suggest or render expedient may be made without departing from the spirit or scope of the appended claims.

What is claimed is:

1. A tension wrench comprising in combination a head portion having oppositely extending hollow arms thereon, a, work engaging boss mounted for rotative movement in said head having a pair of oppositely positioned latch receiving recesses in the outer periphery thereof in normal alignment with the said arms, latch members in said arms inv frictional engagement with the said boss, hollow extensions secured to said arms, handles on the ends oi the said extensions, springs in said extensions, followers in abutting engagement with the said springs, indicators on said followers, a threaded member in said handles whereby the compressive force on the said springs may be kept in balanced relation with each other, and cooperating means on said boss and said head whereby rotative movement of these two elements is limited to an extent which prevents disengagement of said latch members from said latch receiving recesses.

2. A tension wrench comprising in combination a head Vportion having oppositely extending hollow arms thereon, a work engaging. boss mounted for rotative movement in said head having a pair of oppositely positioned latch receiving recesses in the outer periphery thereof in normal alignment with the said arms, latch members in said arms in frictional engagement with the said boss, means connected to said arms for adjusting in balanced relation the force of the frictional engagement of said latch members with said latch receiving recesses, said head also having a stop receiving'recess in the outer periphery thereof between saidvfirst mentioned recesses, and a stop extending through the said head and into the stop receiving recess in the said boss, the stop receiving recess being wider than the stop to permit limited relative rotation between the head portion and the boss to an extent insuillcient to allow a complete disengagement of said latch members from said latch receiving recesses.

3. A tension wrench comprising in combination a head portion having oppositely extending hollow arms thereon, a work engaging boss mounted for rotative movement in said head having a pair of oppositely positioned latch receiving recesses in the outer periphery thereof in normal alignment with the said arms, latch members in said arms in frictional engagement with the said boss, hollow extensions secured to said arms, handles on the ends of the said extensions, springs in said extensions, followers in abutting engagement with the said springs, a threaded member in said handles whereby the compressive force on the said springs may be kept in balanced relation with each other, a stop receiving recess in the outer periphery of said work engaging boss, and a stop extending through the said head and into the stop receiving recess in the said boss, the stop receiving recess being wider than the stop and sufliciently narrow to permit limited movement of the head with respect to the boss and to preventl the latch members from moving entirely out of the latch receiving recesses.

HELENA E. JOHNSON. Executrisc of the Estate of Leonard W. Johnson,

Deceased. 

